     Sudoku Solution Path   Sudoku Puzzle © Kevin Stone R2C1 is the only square in row 2 that can be <6> R7C1 can only be <8> R7C5 can only be <4> R7C7 can only be <2> R7C9 can only be <7> R7C3 can only be <6> R2C5 is the only square in row 2 that can be <7> R2C9 is the only square in row 2 that can be <2> R4C6 is the only square in row 4 that can be <1> R4C4 is the only square in row 4 that can be <7> R4C9 is the only square in row 4 that can be <4> R5C4 is the only square in row 5 that can be <6> R6C4 is the only square in row 6 that can be <4> R9C6 is the only square in row 9 that can be <5> R6C1 is the only square in column 1 that can be <9> R6C6 can only be <8> R1C4 is the only square in row 1 that can be <8> R9C4 can only be <9> R8C5 can only be <8> R9C8 is the only square in row 9 that can be <8> Squares R4C5 and R6C5 in column 5 form a simple locked pair. These 2 squares both contain the 2 possibilities <35>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.    R5C5 - removing <35> from <2359> leaving <29> Squares R2C8 and R5C8 in column 8 form a simple locked pair. These 2 squares both contain the 2 possibilities <13>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.    R1C8 - removing <3> from <349> leaving <49>    R8C8 - removing <3> from <349> leaving <49> Squares R1C2 and R1C7 in row 1 and R5C2 and R5C7 in row 5 form a Simple X-Wing pattern on possibility <5>. All other instances of this possibility in columns 2 and 7 can be removed.    R3C7 - removing <5> from <145> leaving <14> Squares R4C1 and R8C1 in column 1, R4C5 and R6C5 in column 5 and R6C9 and R8C9 in column 9 form a Swordfish pattern on possibility <3>. All other instances of this possibility in rows 4, 6 and 8 can be removed.    R8C2 - removing <3> from <134> leaving <14> Squares R3C1 (XY), R2C2 (XZ) and R4C1 (YZ) form an XY-Wing pattern on <3>. All squares that are buddies of both the XZ and YZ squares cannot be <3>.    R5C2 - removing <3> from <357> leaving <57> Squares R3C7 (XY), R2C8 (XZ) and R9C7 (YZ) form an XY-Wing pattern on <3>. All squares that are buddies of both the XZ and YZ squares cannot be <3>.    R1C7 - removing <3> from <345> leaving <45> R2C8 is the only square in block 3 that can be <3> R2C2 can only be <1> R5C8 can only be <1> R8C2 can only be <4> R3C1 can only be <5> R3C9 can only be <9> R4C1 can only be <3> R3C5 can only be <2> R8C9 can only be <3> R1C8 can only be <4> R4C5 can only be <5> R8C1 can only be <1> R5C3 can only be <7> R6C5 can only be <3> R5C2 can only be <5> R6C9 can only be <5> R5C7 can only be <3> R8C8 can only be <9> R1C2 can only be <3> R9C3 can only be <3> R9C7 can only be <4> R9C2 can only be <7> R1C7 can only be <5> R3C7 can only be <1> R1C3 can only be <2> R3C3 can only be <4> R5C5 can only be <9> R1C6 can only be <9> R5C6 can only be <2>    